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20#include <linux/fs.h>
21#include <linux/file.h>
22#include <linux/pagemap.h>
23#include <linux/splice.h>
24#include <linux/memcontrol.h>
25#include <linux/mm_inline.h>
26#include <linux/swap.h>
27#include <linux/writeback.h>
28#include <linux/module.h>
29#include <linux/syscalls.h>
30#include <linux/uio.h>
31#include <linux/security.h>
32#include <linux/gfp.h>
33
34
35
36
37
38
39
40static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
41 struct pipe_buffer *buf)
42{
43 struct page *page = buf->page;
44 struct address_space *mapping;
45
46 lock_page(page);
47
48 mapping = page_mapping(page);
49 if (mapping) {
50 WARN_ON(!PageUptodate(page));
51
52
53
54
55
56
57
58
59
60 wait_on_page_writeback(page);
61
62 if (page_has_private(page) &&
63 !try_to_release_page(page, GFP_KERNEL))
64 goto out_unlock;
65
66
67
68
69
70 if (remove_mapping(mapping, page)) {
71 buf->flags |= PIPE_BUF_FLAG_LRU;
72 return 0;
73 }
74 }
75
76
77
78
79
80out_unlock:
81 unlock_page(page);
82 return 1;
83}
84
85static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
86 struct pipe_buffer *buf)
87{
88 page_cache_release(buf->page);
89 buf->flags &= ~PIPE_BUF_FLAG_LRU;
90}
91
92
93
94
95
96static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe,
97 struct pipe_buffer *buf)
98{
99 struct page *page = buf->page;
100 int err;
101
102 if (!PageUptodate(page)) {
103 lock_page(page);
104
105
106
107
108
109 if (!page->mapping) {
110 err = -ENODATA;
111 goto error;
112 }
113
114
115
116
117 if (!PageUptodate(page)) {
118 err = -EIO;
119 goto error;
120 }
121
122
123
124
125 unlock_page(page);
126 }
127
128 return 0;
129error:
130 unlock_page(page);
131 return err;
132}
133
134const struct pipe_buf_operations page_cache_pipe_buf_ops = {
135 .can_merge = 0,
136 .map = generic_pipe_buf_map,
137 .unmap = generic_pipe_buf_unmap,
138 .confirm = page_cache_pipe_buf_confirm,
139 .release = page_cache_pipe_buf_release,
140 .steal = page_cache_pipe_buf_steal,
141 .get = generic_pipe_buf_get,
142};
143
144static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
145 struct pipe_buffer *buf)
146{
147 if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
148 return 1;
149
150 buf->flags |= PIPE_BUF_FLAG_LRU;
151 return generic_pipe_buf_steal(pipe, buf);
152}
153
154static const struct pipe_buf_operations user_page_pipe_buf_ops = {
155 .can_merge = 0,
156 .map = generic_pipe_buf_map,
157 .unmap = generic_pipe_buf_unmap,
158 .confirm = generic_pipe_buf_confirm,
159 .release = page_cache_pipe_buf_release,
160 .steal = user_page_pipe_buf_steal,
161 .get = generic_pipe_buf_get,
162};
163
164static void wakeup_pipe_readers(struct pipe_inode_info *pipe)
165{
166 smp_mb();
167 if (waitqueue_active(&pipe->wait))
168 wake_up_interruptible(&pipe->wait);
169 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
170}
171
172
173
174
175
176
177
178
179
180
181
182
183ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
184 struct splice_pipe_desc *spd)
185{
186 unsigned int spd_pages = spd->nr_pages;
187 int ret, do_wakeup, page_nr;
188
189 ret = 0;
190 do_wakeup = 0;
191 page_nr = 0;
192
193 pipe_lock(pipe);
194
195 for (;;) {
196 if (!pipe->readers) {
197 send_sig(SIGPIPE, current, 0);
198 if (!ret)
199 ret = -EPIPE;
200 break;
201 }
202
203 if (pipe->nrbufs < pipe->buffers) {
204 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
205 struct pipe_buffer *buf = pipe->bufs + newbuf;
206
207 buf->page = spd->pages[page_nr];
208 buf->offset = spd->partial[page_nr].offset;
209 buf->len = spd->partial[page_nr].len;
210 buf->private = spd->partial[page_nr].private;
211 buf->ops = spd->ops;
212 if (spd->flags & SPLICE_F_GIFT)
213 buf->flags |= PIPE_BUF_FLAG_GIFT;
214
215 pipe->nrbufs++;
216 page_nr++;
217 ret += buf->len;
218
219 if (pipe->inode)
220 do_wakeup = 1;
221
222 if (!--spd->nr_pages)
223 break;
224 if (pipe->nrbufs < pipe->buffers)
225 continue;
226
227 break;
228 }
229
230 if (spd->flags & SPLICE_F_NONBLOCK) {
231 if (!ret)
232 ret = -EAGAIN;
233 break;
234 }
235
236 if (signal_pending(current)) {
237 if (!ret)
238 ret = -ERESTARTSYS;
239 break;
240 }
241
242 if (do_wakeup) {
243 smp_mb();
244 if (waitqueue_active(&pipe->wait))
245 wake_up_interruptible_sync(&pipe->wait);
246 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
247 do_wakeup = 0;
248 }
249
250 pipe->waiting_writers++;
251 pipe_wait(pipe);
252 pipe->waiting_writers--;
253 }
254
255 pipe_unlock(pipe);
256
257 if (do_wakeup)
258 wakeup_pipe_readers(pipe);
259
260 while (page_nr < spd_pages)
261 spd->spd_release(spd, page_nr++);
262
263 return ret;
264}
265
266void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
267{
268 page_cache_release(spd->pages[i]);
269}
270
271
272
273
274
275int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
276{
277 if (pipe->buffers <= PIPE_DEF_BUFFERS)
278 return 0;
279
280 spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
281 spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
282
283 if (spd->pages && spd->partial)
284 return 0;
285
286 kfree(spd->pages);
287 kfree(spd->partial);
288 return -ENOMEM;
289}
290
291void splice_shrink_spd(struct pipe_inode_info *pipe,
292 struct splice_pipe_desc *spd)
293{
294 if (pipe->buffers <= PIPE_DEF_BUFFERS)
295 return;
296
297 kfree(spd->pages);
298 kfree(spd->partial);
299}
300
301static int
302__generic_file_splice_read(struct file *in, loff_t *ppos,
303 struct pipe_inode_info *pipe, size_t len,
304 unsigned int flags)
305{
306 struct address_space *mapping = in->f_mapping;
307 unsigned int loff, nr_pages, req_pages;
308 struct page *pages[PIPE_DEF_BUFFERS];
309 struct partial_page partial[PIPE_DEF_BUFFERS];
310 struct page *page;
311 pgoff_t index, end_index;
312 loff_t isize;
313 int error, page_nr;
314 struct splice_pipe_desc spd = {
315 .pages = pages,
316 .partial = partial,
317 .flags = flags,
318 .ops = &page_cache_pipe_buf_ops,
319 .spd_release = spd_release_page,
320 };
321
322 if (splice_grow_spd(pipe, &spd))
323 return -ENOMEM;
324
325 index = *ppos >> PAGE_CACHE_SHIFT;
326 loff = *ppos & ~PAGE_CACHE_MASK;
327 req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
328 nr_pages = min(req_pages, pipe->buffers);
329
330
331
332
333 spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages);
334 index += spd.nr_pages;
335
336
337
338
339
340 if (spd.nr_pages < nr_pages)
341 page_cache_sync_readahead(mapping, &in->f_ra, in,
342 index, req_pages - spd.nr_pages);
343
344 error = 0;
345 while (spd.nr_pages < nr_pages) {
346
347
348
349
350 page = find_get_page(mapping, index);
351 if (!page) {
352
353
354
355 page = page_cache_alloc_cold(mapping);
356 if (!page)
357 break;
358
359 error = add_to_page_cache_lru(page, mapping, index,
360 GFP_KERNEL);
361 if (unlikely(error)) {
362 page_cache_release(page);
363 if (error == -EEXIST)
364 continue;
365 break;
366 }
367
368
369
370
371 unlock_page(page);
372 }
373
374 spd.pages[spd.nr_pages++] = page;
375 index++;
376 }
377
378
379
380
381
382 index = *ppos >> PAGE_CACHE_SHIFT;
383 nr_pages = spd.nr_pages;
384 spd.nr_pages = 0;
385 for (page_nr = 0; page_nr < nr_pages; page_nr++) {
386 unsigned int this_len;
387
388 if (!len)
389 break;
390
391
392
393
394 this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
395 page = spd.pages[page_nr];
396
397 if (PageReadahead(page))
398 page_cache_async_readahead(mapping, &in->f_ra, in,
399 page, index, req_pages - page_nr);
400
401
402
403
404 if (!PageUptodate(page)) {
405 lock_page(page);
406
407
408
409
410
411
412
413 if (!page->mapping) {
414 unlock_page(page);
415 page = find_or_create_page(mapping, index,
416 mapping_gfp_mask(mapping));
417
418 if (!page) {
419 error = -ENOMEM;
420 break;
421 }
422 page_cache_release(spd.pages[page_nr]);
423 spd.pages[page_nr] = page;
424 }
425
426
427
428 if (PageUptodate(page)) {
429 unlock_page(page);
430 goto fill_it;
431 }
432
433
434
435
436 error = mapping->a_ops->readpage(in, page);
437 if (unlikely(error)) {
438
439
440
441
442
443
444 if (error == AOP_TRUNCATED_PAGE)
445 error = 0;
446
447 break;
448 }
449 }
450fill_it:
451
452
453
454 isize = i_size_read(mapping->host);
455 end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
456 if (unlikely(!isize || index > end_index))
457 break;
458
459
460
461
462
463 if (end_index == index) {
464 unsigned int plen;
465
466
467
468
469 plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
470 if (plen <= loff)
471 break;
472
473
474
475
476 this_len = min(this_len, plen - loff);
477 len = this_len;
478 }
479
480 spd.partial[page_nr].offset = loff;
481 spd.partial[page_nr].len = this_len;
482 len -= this_len;
483 loff = 0;
484 spd.nr_pages++;
485 index++;
486 }
487
488
489
490
491
492 while (page_nr < nr_pages)
493 page_cache_release(spd.pages[page_nr++]);
494 in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
495
496 if (spd.nr_pages)
497 error = splice_to_pipe(pipe, &spd);
498
499 splice_shrink_spd(pipe, &spd);
500 return error;
501}
502
503
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515
516
517ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
518 struct pipe_inode_info *pipe, size_t len,
519 unsigned int flags)
520{
521 loff_t isize, left;
522 int ret;
523
524 isize = i_size_read(in->f_mapping->host);
525 if (unlikely(*ppos >= isize))
526 return 0;
527
528 left = isize - *ppos;
529 if (unlikely(left < len))
530 len = left;
531
532 ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
533 if (ret > 0) {
534 *ppos += ret;
535 file_accessed(in);
536 }
537
538 return ret;
539}
540EXPORT_SYMBOL(generic_file_splice_read);
541
542static const struct pipe_buf_operations default_pipe_buf_ops = {
543 .can_merge = 0,
544 .map = generic_pipe_buf_map,
545 .unmap = generic_pipe_buf_unmap,
546 .confirm = generic_pipe_buf_confirm,
547 .release = generic_pipe_buf_release,
548 .steal = generic_pipe_buf_steal,
549 .get = generic_pipe_buf_get,
550};
551
552static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
553 unsigned long vlen, loff_t offset)
554{
555 mm_segment_t old_fs;
556 loff_t pos = offset;
557 ssize_t res;
558
559 old_fs = get_fs();
560 set_fs(get_ds());
561
562 res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
563 set_fs(old_fs);
564
565 return res;
566}
567
568static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
569 loff_t pos)
570{
571 mm_segment_t old_fs;
572 ssize_t res;
573
574 old_fs = get_fs();
575 set_fs(get_ds());
576
577 res = vfs_write(file, (const char __user *)buf, count, &pos);
578 set_fs(old_fs);
579
580 return res;
581}
582
583ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
584 struct pipe_inode_info *pipe, size_t len,
585 unsigned int flags)
586{
587 unsigned int nr_pages;
588 unsigned int nr_freed;
589 size_t offset;
590 struct page *pages[PIPE_DEF_BUFFERS];
591 struct partial_page partial[PIPE_DEF_BUFFERS];
592 struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
593 ssize_t res;
594 size_t this_len;
595 int error;
596 int i;
597 struct splice_pipe_desc spd = {
598 .pages = pages,
599 .partial = partial,
600 .flags = flags,
601 .ops = &default_pipe_buf_ops,
602 .spd_release = spd_release_page,
603 };
604
605 if (splice_grow_spd(pipe, &spd))
606 return -ENOMEM;
607
608 res = -ENOMEM;
609 vec = __vec;
610 if (pipe->buffers > PIPE_DEF_BUFFERS) {
611 vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
612 if (!vec)
613 goto shrink_ret;
614 }
615
616 offset = *ppos & ~PAGE_CACHE_MASK;
617 nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
618
619 for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
620 struct page *page;
621
622 page = alloc_page(GFP_USER);
623 error = -ENOMEM;
624 if (!page)
625 goto err;
626
627 this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset);
628 vec[i].iov_base = (void __user *) page_address(page);
629 vec[i].iov_len = this_len;
630 spd.pages[i] = page;
631 spd.nr_pages++;
632 len -= this_len;
633 offset = 0;
634 }
635
636 res = kernel_readv(in, vec, spd.nr_pages, *ppos);
637 if (res < 0) {
638 error = res;
639 goto err;
640 }
641
642 error = 0;
643 if (!res)
644 goto err;
645
646 nr_freed = 0;
647 for (i = 0; i < spd.nr_pages; i++) {
648 this_len = min_t(size_t, vec[i].iov_len, res);
649 spd.partial[i].offset = 0;
650 spd.partial[i].len = this_len;
651 if (!this_len) {
652 __free_page(spd.pages[i]);
653 spd.pages[i] = NULL;
654 nr_freed++;
655 }
656 res -= this_len;
657 }
658 spd.nr_pages -= nr_freed;
659
660 res = splice_to_pipe(pipe, &spd);
661 if (res > 0)
662 *ppos += res;
663
664shrink_ret:
665 if (vec != __vec)
666 kfree(vec);
667 splice_shrink_spd(pipe, &spd);
668 return res;
669
670err:
671 for (i = 0; i < spd.nr_pages; i++)
672 __free_page(spd.pages[i]);
673
674 res = error;
675 goto shrink_ret;
676}
677EXPORT_SYMBOL(default_file_splice_read);
678
679
680
681
682
683static int pipe_to_sendpage(struct pipe_inode_info *pipe,
684 struct pipe_buffer *buf, struct splice_desc *sd)
685{
686 struct file *file = sd->u.file;
687 loff_t pos = sd->pos;
688 int more;
689
690 if (!likely(file->f_op && file->f_op->sendpage))
691 return -EINVAL;
692
693 more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
694 return file->f_op->sendpage(file, buf->page, buf->offset,
695 sd->len, &pos, more);
696}
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716
717
718int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
719 struct splice_desc *sd)
720{
721 struct file *file = sd->u.file;
722 struct address_space *mapping = file->f_mapping;
723 unsigned int offset, this_len;
724 struct page *page;
725 void *fsdata;
726 int ret;
727
728 offset = sd->pos & ~PAGE_CACHE_MASK;
729
730 this_len = sd->len;
731 if (this_len + offset > PAGE_CACHE_SIZE)
732 this_len = PAGE_CACHE_SIZE - offset;
733
734 ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
735 AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
736 if (unlikely(ret))
737 goto out;
738
739 if (buf->page != page) {
740
741
742
743 char *src = buf->ops->map(pipe, buf, 1);
744 char *dst = kmap_atomic(page, KM_USER1);
745
746 memcpy(dst + offset, src + buf->offset, this_len);
747 flush_dcache_page(page);
748 kunmap_atomic(dst, KM_USER1);
749 buf->ops->unmap(pipe, buf, src);
750 }
751 ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
752 page, fsdata);
753out:
754 return ret;
755}
756EXPORT_SYMBOL(pipe_to_file);
757
758static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
759{
760 smp_mb();
761 if (waitqueue_active(&pipe->wait))
762 wake_up_interruptible(&pipe->wait);
763 kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
764}
765
766
767
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784
785
786int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
787 splice_actor *actor)
788{
789 int ret;
790
791 while (pipe->nrbufs) {
792 struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
793 const struct pipe_buf_operations *ops = buf->ops;
794
795 sd->len = buf->len;
796 if (sd->len > sd->total_len)
797 sd->len = sd->total_len;
798
799 ret = buf->ops->confirm(pipe, buf);
800 if (unlikely(ret)) {
801 if (ret == -ENODATA)
802 ret = 0;
803 return ret;
804 }
805
806 ret = actor(pipe, buf, sd);
807 if (ret <= 0)
808 return ret;
809
810 buf->offset += ret;
811 buf->len -= ret;
812
813 sd->num_spliced += ret;
814 sd->len -= ret;
815 sd->pos += ret;
816 sd->total_len -= ret;
817
818 if (!buf->len) {
819 buf->ops = NULL;
820 ops->release(pipe, buf);
821 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
822 pipe->nrbufs--;
823 if (pipe->inode)
824 sd->need_wakeup = true;
825 }
826
827 if (!sd->total_len)
828 return 0;
829 }
830
831 return 1;
832}
833EXPORT_SYMBOL(splice_from_pipe_feed);
834
835
836
837
838
839
840
841
842
843
844
845int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
846{
847 while (!pipe->nrbufs) {
848 if (!pipe->writers)
849 return 0;
850
851 if (!pipe->waiting_writers && sd->num_spliced)
852 return 0;
853
854 if (sd->flags & SPLICE_F_NONBLOCK)
855 return -EAGAIN;
856
857 if (signal_pending(current))
858 return -ERESTARTSYS;
859
860 if (sd->need_wakeup) {
861 wakeup_pipe_writers(pipe);
862 sd->need_wakeup = false;
863 }
864
865 pipe_wait(pipe);
866 }
867
868 return 1;
869}
870EXPORT_SYMBOL(splice_from_pipe_next);
871
872
873
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875
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878
879
880
881void splice_from_pipe_begin(struct splice_desc *sd)
882{
883 sd->num_spliced = 0;
884 sd->need_wakeup = false;
885}
886EXPORT_SYMBOL(splice_from_pipe_begin);
887
888
889
890
891
892
893
894
895
896
897
898void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
899{
900 if (sd->need_wakeup)
901 wakeup_pipe_writers(pipe);
902}
903EXPORT_SYMBOL(splice_from_pipe_end);
904
905
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913
914
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916
917
918ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
919 splice_actor *actor)
920{
921 int ret;
922
923 splice_from_pipe_begin(sd);
924 do {
925 ret = splice_from_pipe_next(pipe, sd);
926 if (ret > 0)
927 ret = splice_from_pipe_feed(pipe, sd, actor);
928 } while (ret > 0);
929 splice_from_pipe_end(pipe, sd);
930
931 return sd->num_spliced ? sd->num_spliced : ret;
932}
933EXPORT_SYMBOL(__splice_from_pipe);
934
935
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940
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948
949ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
950 loff_t *ppos, size_t len, unsigned int flags,
951 splice_actor *actor)
952{
953 ssize_t ret;
954 struct splice_desc sd = {
955 .total_len = len,
956 .flags = flags,
957 .pos = *ppos,
958 .u.file = out,
959 };
960
961 pipe_lock(pipe);
962 ret = __splice_from_pipe(pipe, &sd, actor);
963 pipe_unlock(pipe);
964
965 return ret;
966}
967
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975
976
977
978
979
980
981ssize_t
982generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
983 loff_t *ppos, size_t len, unsigned int flags)
984{
985 struct address_space *mapping = out->f_mapping;
986 struct inode *inode = mapping->host;
987 struct splice_desc sd = {
988 .total_len = len,
989 .flags = flags,
990 .pos = *ppos,
991 .u.file = out,
992 };
993 ssize_t ret;
994
995 pipe_lock(pipe);
996
997 splice_from_pipe_begin(&sd);
998 do {
999 ret = splice_from_pipe_next(pipe, &sd);
1000 if (ret <= 0)
1001 break;
1002
1003 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1004 ret = file_remove_suid(out);
1005 if (!ret) {
1006 file_update_time(out);
1007 ret = splice_from_pipe_feed(pipe, &sd, pipe_to_file);
1008 }
1009 mutex_unlock(&inode->i_mutex);
1010 } while (ret > 0);
1011 splice_from_pipe_end(pipe, &sd);
1012
1013 pipe_unlock(pipe);
1014
1015 if (sd.num_spliced)
1016 ret = sd.num_spliced;
1017
1018 if (ret > 0) {
1019 unsigned long nr_pages;
1020 int err;
1021
1022 nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1023
1024 err = generic_write_sync(out, *ppos, ret);
1025 if (err)
1026 ret = err;
1027 else
1028 *ppos += ret;
1029 balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
1030 }
1031
1032 return ret;
1033}
1034
1035EXPORT_SYMBOL(generic_file_splice_write);
1036
1037static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
1038 struct splice_desc *sd)
1039{
1040 int ret;
1041 void *data;
1042
1043 data = buf->ops->map(pipe, buf, 0);
1044 ret = kernel_write(sd->u.file, data + buf->offset, sd->len, sd->pos);
1045 buf->ops->unmap(pipe, buf, data);
1046
1047 return ret;
1048}
1049
1050static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
1051 struct file *out, loff_t *ppos,
1052 size_t len, unsigned int flags)
1053{
1054 ssize_t ret;
1055
1056 ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
1057 if (ret > 0)
1058 *ppos += ret;
1059
1060 return ret;
1061}
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
1077 loff_t *ppos, size_t len, unsigned int flags)
1078{
1079 return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
1080}
1081
1082EXPORT_SYMBOL(generic_splice_sendpage);
1083
1084
1085
1086
1087static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
1088 loff_t *ppos, size_t len, unsigned int flags)
1089{
1090 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
1091 loff_t *, size_t, unsigned int);
1092 int ret;
1093
1094 if (unlikely(!(out->f_mode & FMODE_WRITE)))
1095 return -EBADF;
1096
1097 if (unlikely(out->f_flags & O_APPEND))
1098 return -EINVAL;
1099
1100 ret = rw_verify_area(WRITE, out, ppos, len);
1101 if (unlikely(ret < 0))
1102 return ret;
1103
1104 if (out->f_op && out->f_op->splice_write)
1105 splice_write = out->f_op->splice_write;
1106 else
1107 splice_write = default_file_splice_write;
1108
1109 return splice_write(pipe, out, ppos, len, flags);
1110}
1111
1112
1113
1114
1115static long do_splice_to(struct file *in, loff_t *ppos,
1116 struct pipe_inode_info *pipe, size_t len,
1117 unsigned int flags)
1118{
1119 ssize_t (*splice_read)(struct file *, loff_t *,
1120 struct pipe_inode_info *, size_t, unsigned int);
1121 int ret;
1122
1123 if (unlikely(!(in->f_mode & FMODE_READ)))
1124 return -EBADF;
1125
1126 ret = rw_verify_area(READ, in, ppos, len);
1127 if (unlikely(ret < 0))
1128 return ret;
1129
1130 if (in->f_op && in->f_op->splice_read)
1131 splice_read = in->f_op->splice_read;
1132 else
1133 splice_read = default_file_splice_read;
1134
1135 return splice_read(in, ppos, pipe, len, flags);
1136}
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
1152 splice_direct_actor *actor)
1153{
1154 struct pipe_inode_info *pipe;
1155 long ret, bytes;
1156 umode_t i_mode;
1157 size_t len;
1158 int i, flags;
1159
1160
1161
1162
1163
1164
1165 i_mode = in->f_path.dentry->d_inode->i_mode;
1166 if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode)))
1167 return -EINVAL;
1168
1169
1170
1171
1172
1173 pipe = current->splice_pipe;
1174 if (unlikely(!pipe)) {
1175 pipe = alloc_pipe_info(NULL);
1176 if (!pipe)
1177 return -ENOMEM;
1178
1179
1180
1181
1182
1183
1184 pipe->readers = 1;
1185
1186 current->splice_pipe = pipe;
1187 }
1188
1189
1190
1191
1192 ret = 0;
1193 bytes = 0;
1194 len = sd->total_len;
1195 flags = sd->flags;
1196
1197
1198
1199
1200 sd->flags &= ~SPLICE_F_NONBLOCK;
1201
1202 while (len) {
1203 size_t read_len;
1204 loff_t pos = sd->pos, prev_pos = pos;
1205
1206 ret = do_splice_to(in, &pos, pipe, len, flags);
1207 if (unlikely(ret <= 0))
1208 goto out_release;
1209
1210 read_len = ret;
1211 sd->total_len = read_len;
1212
1213
1214
1215
1216
1217
1218 ret = actor(pipe, sd);
1219 if (unlikely(ret <= 0)) {
1220 sd->pos = prev_pos;
1221 goto out_release;
1222 }
1223
1224 bytes += ret;
1225 len -= ret;
1226 sd->pos = pos;
1227
1228 if (ret < read_len) {
1229 sd->pos = prev_pos + ret;
1230 goto out_release;
1231 }
1232 }
1233
1234done:
1235 pipe->nrbufs = pipe->curbuf = 0;
1236 file_accessed(in);
1237 return bytes;
1238
1239out_release:
1240
1241
1242
1243
1244 for (i = 0; i < pipe->buffers; i++) {
1245 struct pipe_buffer *buf = pipe->bufs + i;
1246
1247 if (buf->ops) {
1248 buf->ops->release(pipe, buf);
1249 buf->ops = NULL;
1250 }
1251 }
1252
1253 if (!bytes)
1254 bytes = ret;
1255
1256 goto done;
1257}
1258EXPORT_SYMBOL(splice_direct_to_actor);
1259
1260static int direct_splice_actor(struct pipe_inode_info *pipe,
1261 struct splice_desc *sd)
1262{
1263 struct file *file = sd->u.file;
1264
1265 return do_splice_from(pipe, file, &file->f_pos, sd->total_len,
1266 sd->flags);
1267}
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
1285 size_t len, unsigned int flags)
1286{
1287 struct splice_desc sd = {
1288 .len = len,
1289 .total_len = len,
1290 .flags = flags,
1291 .pos = *ppos,
1292 .u.file = out,
1293 };
1294 long ret;
1295
1296 ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
1297 if (ret > 0)
1298 *ppos = sd.pos;
1299
1300 return ret;
1301}
1302
1303static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1304 struct pipe_inode_info *opipe,
1305 size_t len, unsigned int flags);
1306
1307
1308
1309
1310static long do_splice(struct file *in, loff_t __user *off_in,
1311 struct file *out, loff_t __user *off_out,
1312 size_t len, unsigned int flags)
1313{
1314 struct pipe_inode_info *ipipe;
1315 struct pipe_inode_info *opipe;
1316 loff_t offset, *off;
1317 long ret;
1318
1319 ipipe = get_pipe_info(in);
1320 opipe = get_pipe_info(out);
1321
1322 if (ipipe && opipe) {
1323 if (off_in || off_out)
1324 return -ESPIPE;
1325
1326 if (!(in->f_mode & FMODE_READ))
1327 return -EBADF;
1328
1329 if (!(out->f_mode & FMODE_WRITE))
1330 return -EBADF;
1331
1332
1333 if (ipipe == opipe)
1334 return -EINVAL;
1335
1336 return splice_pipe_to_pipe(ipipe, opipe, len, flags);
1337 }
1338
1339 if (ipipe) {
1340 if (off_in)
1341 return -ESPIPE;
1342 if (off_out) {
1343 if (!(out->f_mode & FMODE_PWRITE))
1344 return -EINVAL;
1345 if (copy_from_user(&offset, off_out, sizeof(loff_t)))
1346 return -EFAULT;
1347 off = &offset;
1348 } else
1349 off = &out->f_pos;
1350
1351 ret = do_splice_from(ipipe, out, off, len, flags);
1352
1353 if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
1354 ret = -EFAULT;
1355
1356 return ret;
1357 }
1358
1359 if (opipe) {
1360 if (off_out)
1361 return -ESPIPE;
1362 if (off_in) {
1363 if (!(in->f_mode & FMODE_PREAD))
1364 return -EINVAL;
1365 if (copy_from_user(&offset, off_in, sizeof(loff_t)))
1366 return -EFAULT;
1367 off = &offset;
1368 } else
1369 off = &in->f_pos;
1370
1371 ret = do_splice_to(in, off, opipe, len, flags);
1372
1373 if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
1374 ret = -EFAULT;
1375
1376 return ret;
1377 }
1378
1379 return -EINVAL;
1380}
1381
1382
1383
1384
1385
1386
1387
1388
1389static int get_iovec_page_array(const struct iovec __user *iov,
1390 unsigned int nr_vecs, struct page **pages,
1391 struct partial_page *partial, int aligned,
1392 unsigned int pipe_buffers)
1393{
1394 int buffers = 0, error = 0;
1395
1396 while (nr_vecs) {
1397 unsigned long off, npages;
1398 struct iovec entry;
1399 void __user *base;
1400 size_t len;
1401 int i;
1402
1403 error = -EFAULT;
1404 if (copy_from_user(&entry, iov, sizeof(entry)))
1405 break;
1406
1407 base = entry.iov_base;
1408 len = entry.iov_len;
1409
1410
1411
1412
1413 error = 0;
1414 if (unlikely(!len))
1415 break;
1416 error = -EFAULT;
1417 if (!access_ok(VERIFY_READ, base, len))
1418 break;
1419
1420
1421
1422
1423
1424 off = (unsigned long) base & ~PAGE_MASK;
1425
1426
1427
1428
1429
1430 error = -EINVAL;
1431 if (aligned && (off || len & ~PAGE_MASK))
1432 break;
1433
1434 npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1435 if (npages > pipe_buffers - buffers)
1436 npages = pipe_buffers - buffers;
1437
1438 error = get_user_pages_fast((unsigned long)base, npages,
1439 0, &pages[buffers]);
1440
1441 if (unlikely(error <= 0))
1442 break;
1443
1444
1445
1446
1447 for (i = 0; i < error; i++) {
1448 const int plen = min_t(size_t, len, PAGE_SIZE - off);
1449
1450 partial[buffers].offset = off;
1451 partial[buffers].len = plen;
1452
1453 off = 0;
1454 len -= plen;
1455 buffers++;
1456 }
1457
1458
1459
1460
1461
1462
1463 if (len)
1464 break;
1465
1466
1467
1468
1469
1470
1471 if (error < npages || buffers == pipe_buffers)
1472 break;
1473
1474 nr_vecs--;
1475 iov++;
1476 }
1477
1478 if (buffers)
1479 return buffers;
1480
1481 return error;
1482}
1483
1484static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
1485 struct splice_desc *sd)
1486{
1487 char *src;
1488 int ret;
1489
1490
1491
1492
1493
1494 if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) {
1495 src = buf->ops->map(pipe, buf, 1);
1496 ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset,
1497 sd->len);
1498 buf->ops->unmap(pipe, buf, src);
1499 if (!ret) {
1500 ret = sd->len;
1501 goto out;
1502 }
1503 }
1504
1505
1506
1507
1508 src = buf->ops->map(pipe, buf, 0);
1509
1510 ret = sd->len;
1511 if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len))
1512 ret = -EFAULT;
1513
1514 buf->ops->unmap(pipe, buf, src);
1515out:
1516 if (ret > 0)
1517 sd->u.userptr += ret;
1518 return ret;
1519}
1520
1521
1522
1523
1524
1525static long vmsplice_to_user(struct file *file, const struct iovec __user *iov,
1526 unsigned long nr_segs, unsigned int flags)
1527{
1528 struct pipe_inode_info *pipe;
1529 struct splice_desc sd;
1530 ssize_t size;
1531 int error;
1532 long ret;
1533
1534 pipe = get_pipe_info(file);
1535 if (!pipe)
1536 return -EBADF;
1537
1538 pipe_lock(pipe);
1539
1540 error = ret = 0;
1541 while (nr_segs) {
1542 void __user *base;
1543 size_t len;
1544
1545
1546
1547
1548 error = get_user(base, &iov->iov_base);
1549 if (unlikely(error))
1550 break;
1551 error = get_user(len, &iov->iov_len);
1552 if (unlikely(error))
1553 break;
1554
1555
1556
1557
1558 if (unlikely(!len))
1559 break;
1560 if (unlikely(!base)) {
1561 error = -EFAULT;
1562 break;
1563 }
1564
1565 if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
1566 error = -EFAULT;
1567 break;
1568 }
1569
1570 sd.len = 0;
1571 sd.total_len = len;
1572 sd.flags = flags;
1573 sd.u.userptr = base;
1574 sd.pos = 0;
1575
1576 size = __splice_from_pipe(pipe, &sd, pipe_to_user);
1577 if (size < 0) {
1578 if (!ret)
1579 ret = size;
1580
1581 break;
1582 }
1583
1584 ret += size;
1585
1586 if (size < len)
1587 break;
1588
1589 nr_segs--;
1590 iov++;
1591 }
1592
1593 pipe_unlock(pipe);
1594
1595 if (!ret)
1596 ret = error;
1597
1598 return ret;
1599}
1600
1601
1602
1603
1604
1605
1606static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
1607 unsigned long nr_segs, unsigned int flags)
1608{
1609 struct pipe_inode_info *pipe;
1610 struct page *pages[PIPE_DEF_BUFFERS];
1611 struct partial_page partial[PIPE_DEF_BUFFERS];
1612 struct splice_pipe_desc spd = {
1613 .pages = pages,
1614 .partial = partial,
1615 .flags = flags,
1616 .ops = &user_page_pipe_buf_ops,
1617 .spd_release = spd_release_page,
1618 };
1619 long ret;
1620
1621 pipe = get_pipe_info(file);
1622 if (!pipe)
1623 return -EBADF;
1624
1625 if (splice_grow_spd(pipe, &spd))
1626 return -ENOMEM;
1627
1628 spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
1629 spd.partial, flags & SPLICE_F_GIFT,
1630 pipe->buffers);
1631 if (spd.nr_pages <= 0)
1632 ret = spd.nr_pages;
1633 else
1634 ret = splice_to_pipe(pipe, &spd);
1635
1636 splice_shrink_spd(pipe, &spd);
1637 return ret;
1638}
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov,
1657 unsigned long, nr_segs, unsigned int, flags)
1658{
1659 struct file *file;
1660 long error;
1661 int fput;
1662
1663 if (unlikely(nr_segs > UIO_MAXIOV))
1664 return -EINVAL;
1665 else if (unlikely(!nr_segs))
1666 return 0;
1667
1668 error = -EBADF;
1669 file = fget_light(fd, &fput);
1670 if (file) {
1671 if (file->f_mode & FMODE_WRITE)
1672 error = vmsplice_to_pipe(file, iov, nr_segs, flags);
1673 else if (file->f_mode & FMODE_READ)
1674 error = vmsplice_to_user(file, iov, nr_segs, flags);
1675
1676 fput_light(file, fput);
1677 }
1678
1679 return error;
1680}
1681
1682SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in,
1683 int, fd_out, loff_t __user *, off_out,
1684 size_t, len, unsigned int, flags)
1685{
1686 long error;
1687 struct file *in, *out;
1688 int fput_in, fput_out;
1689
1690 if (unlikely(!len))
1691 return 0;
1692
1693 error = -EBADF;
1694 in = fget_light(fd_in, &fput_in);
1695 if (in) {
1696 if (in->f_mode & FMODE_READ) {
1697 out = fget_light(fd_out, &fput_out);
1698 if (out) {
1699 if (out->f_mode & FMODE_WRITE)
1700 error = do_splice(in, off_in,
1701 out, off_out,
1702 len, flags);
1703 fput_light(out, fput_out);
1704 }
1705 }
1706
1707 fput_light(in, fput_in);
1708 }
1709
1710 return error;
1711}
1712
1713
1714
1715
1716
1717static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
1718{
1719 int ret;
1720
1721
1722
1723
1724
1725 if (pipe->nrbufs)
1726 return 0;
1727
1728 ret = 0;
1729 pipe_lock(pipe);
1730
1731 while (!pipe->nrbufs) {
1732 if (signal_pending(current)) {
1733 ret = -ERESTARTSYS;
1734 break;
1735 }
1736 if (!pipe->writers)
1737 break;
1738 if (!pipe->waiting_writers) {
1739 if (flags & SPLICE_F_NONBLOCK) {
1740 ret = -EAGAIN;
1741 break;
1742 }
1743 }
1744 pipe_wait(pipe);
1745 }
1746
1747 pipe_unlock(pipe);
1748 return ret;
1749}
1750
1751
1752
1753
1754
1755static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
1756{
1757 int ret;
1758
1759
1760
1761
1762
1763 if (pipe->nrbufs < pipe->buffers)
1764 return 0;
1765
1766 ret = 0;
1767 pipe_lock(pipe);
1768
1769 while (pipe->nrbufs >= pipe->buffers) {
1770 if (!pipe->readers) {
1771 send_sig(SIGPIPE, current, 0);
1772 ret = -EPIPE;
1773 break;
1774 }
1775 if (flags & SPLICE_F_NONBLOCK) {
1776 ret = -EAGAIN;
1777 break;
1778 }
1779 if (signal_pending(current)) {
1780 ret = -ERESTARTSYS;
1781 break;
1782 }
1783 pipe->waiting_writers++;
1784 pipe_wait(pipe);
1785 pipe->waiting_writers--;
1786 }
1787
1788 pipe_unlock(pipe);
1789 return ret;
1790}
1791
1792
1793
1794
1795static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1796 struct pipe_inode_info *opipe,
1797 size_t len, unsigned int flags)
1798{
1799 struct pipe_buffer *ibuf, *obuf;
1800 int ret = 0, nbuf;
1801 bool input_wakeup = false;
1802
1803
1804retry:
1805 ret = ipipe_prep(ipipe, flags);
1806 if (ret)
1807 return ret;
1808
1809 ret = opipe_prep(opipe, flags);
1810 if (ret)
1811 return ret;
1812
1813
1814
1815
1816
1817
1818 pipe_double_lock(ipipe, opipe);
1819
1820 do {
1821 if (!opipe->readers) {
1822 send_sig(SIGPIPE, current, 0);
1823 if (!ret)
1824 ret = -EPIPE;
1825 break;
1826 }
1827
1828 if (!ipipe->nrbufs && !ipipe->writers)
1829 break;
1830
1831
1832
1833
1834
1835 if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
1836
1837 if (ret)
1838 break;
1839
1840 if (flags & SPLICE_F_NONBLOCK) {
1841 ret = -EAGAIN;
1842 break;
1843 }
1844
1845
1846
1847
1848
1849
1850 pipe_unlock(ipipe);
1851 pipe_unlock(opipe);
1852 goto retry;
1853 }
1854
1855 ibuf = ipipe->bufs + ipipe->curbuf;
1856 nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
1857 obuf = opipe->bufs + nbuf;
1858
1859 if (len >= ibuf->len) {
1860
1861
1862
1863 *obuf = *ibuf;
1864 ibuf->ops = NULL;
1865 opipe->nrbufs++;
1866 ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
1867 ipipe->nrbufs--;
1868 input_wakeup = true;
1869 } else {
1870
1871
1872
1873
1874 ibuf->ops->get(ipipe, ibuf);
1875 *obuf = *ibuf;
1876
1877
1878
1879
1880
1881 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1882
1883 obuf->len = len;
1884 opipe->nrbufs++;
1885 ibuf->offset += obuf->len;
1886 ibuf->len -= obuf->len;
1887 }
1888 ret += obuf->len;
1889 len -= obuf->len;
1890 } while (len);
1891
1892 pipe_unlock(ipipe);
1893 pipe_unlock(opipe);
1894
1895
1896
1897
1898 if (ret > 0)
1899 wakeup_pipe_readers(opipe);
1900
1901 if (input_wakeup)
1902 wakeup_pipe_writers(ipipe);
1903
1904 return ret;
1905}
1906
1907
1908
1909
1910static int link_pipe(struct pipe_inode_info *ipipe,
1911 struct pipe_inode_info *opipe,
1912 size_t len, unsigned int flags)
1913{
1914 struct pipe_buffer *ibuf, *obuf;
1915 int ret = 0, i = 0, nbuf;
1916
1917
1918
1919
1920
1921
1922 pipe_double_lock(ipipe, opipe);
1923
1924 do {
1925 if (!opipe->readers) {
1926 send_sig(SIGPIPE, current, 0);
1927 if (!ret)
1928 ret = -EPIPE;
1929 break;
1930 }
1931
1932
1933
1934
1935
1936 if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
1937 break;
1938
1939 ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
1940 nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
1941
1942
1943
1944
1945
1946 ibuf->ops->get(ipipe, ibuf);
1947
1948 obuf = opipe->bufs + nbuf;
1949 *obuf = *ibuf;
1950
1951
1952
1953
1954
1955 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1956
1957 if (obuf->len > len)
1958 obuf->len = len;
1959
1960 opipe->nrbufs++;
1961 ret += obuf->len;
1962 len -= obuf->len;
1963 i++;
1964 } while (len);
1965
1966
1967
1968
1969
1970 if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK))
1971 ret = -EAGAIN;
1972
1973 pipe_unlock(ipipe);
1974 pipe_unlock(opipe);
1975
1976
1977
1978
1979 if (ret > 0)
1980 wakeup_pipe_readers(opipe);
1981
1982 return ret;
1983}
1984
1985
1986
1987
1988
1989
1990
1991static long do_tee(struct file *in, struct file *out, size_t len,
1992 unsigned int flags)
1993{
1994 struct pipe_inode_info *ipipe = get_pipe_info(in);
1995 struct pipe_inode_info *opipe = get_pipe_info(out);
1996 int ret = -EINVAL;
1997
1998
1999
2000
2001
2002 if (ipipe && opipe && ipipe != opipe) {
2003
2004
2005
2006
2007 ret = ipipe_prep(ipipe, flags);
2008 if (!ret) {
2009 ret = opipe_prep(opipe, flags);
2010 if (!ret)
2011 ret = link_pipe(ipipe, opipe, len, flags);
2012 }
2013 }
2014
2015 return ret;
2016}
2017
2018SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
2019{
2020 struct file *in;
2021 int error, fput_in;
2022
2023 if (unlikely(!len))
2024 return 0;
2025
2026 error = -EBADF;
2027 in = fget_light(fdin, &fput_in);
2028 if (in) {
2029 if (in->f_mode & FMODE_READ) {
2030 int fput_out;
2031 struct file *out = fget_light(fdout, &fput_out);
2032
2033 if (out) {
2034 if (out->f_mode & FMODE_WRITE)
2035 error = do_tee(in, out, len, flags);
2036 fput_light(out, fput_out);
2037 }
2038 }
2039 fput_light(in, fput_in);
2040 }
2041
2042 return error;
2043}
2044